The bill, which is now on the governor's desk, pits privacy advocates against law enforcement interests in managing the emerging technology.
Drones may seem like a dream for law enforcement agencies wanting to put cameras in the sky for easy airborne surveillance, but a bill that sailed through the California legislature seeks to require a warrant for all but the most urgent spying.
Introduced by Republican Assemblyman Jeff Gorell, the would-be law, known as the Unmanned Aircraft Systems bill, easily passed both houses of California's Democratic-majority legislature late last month. It is now awaiting Gov. Jerry Brown's signature. Brown has until the end of September to make a decision.
Although the bill addresses and permits many non-law enforcement uses by government agencies of drones -- which it refers to formally as "civil unmanned aircraft systems" -- the heart of the proposed law is geared toward ensuring that police obtain court-issued warrants before deploying the flying devices for most surveillance.
To many, that's key given that drones equipped with sophisticated camera equipment are increasingly able to hover quietly and for long periods of time at altitudes well below where helicopters, which police have long used for warrantless surveillance, can fly.
The legislation, AB 1327, would allow police free use of drones in "emergency situations" such as fires, hostage crises, chases, and search and rescue, as well as to help first responders, among other situations. But beyond that, the bill would require probable cause and a court-issued warrant.
"The [US] Federal Aviation Administration, by 2015, has been mandated by Congress to authorize drones to be integrated into our airspace, and so it's on our doorstep," said Sam Chung, Gorell's policy director. "Right around the corner, drones will be integrated into our airspace. So it's up to states to implement common sense privacy laws."
The FAA's mandate comes even as NASA has begun an effort to implement a traffic management program, much like that which oversees standard aircraft, for commercial drones.
Added Chung, "We wanted to put in privacy restrictions so the public is assured it's not going to be monitored" without a warrant.
For now, it's unclear what decision Brown will make. A spokesperson told CNET that the governor doesn't comment on pending legislation.
To date, according to Parker Higgins, an activist with Electronic Frontier Foundation, an online First-Amendment advocacy non-profit, there are six states that have already enacted laws requiring police to obtain warrants for drone surveillance.
But it's no surprise that battle lines over the California bill are being drawn, with major media organizations and privacy advocates on one side, and law enforcement groups on the other. Yet Chung also pointed out that Los Angeles Mayor Eric Garcetti -- who oversees that city's police department -- is supporting it and is expected to make a public statement in its favor today.
Still, in an open letter to Brown, the California Police Chiefs Association wrote that "We find it incongruous to hinder law enforcement's utilization of this developing technology....AB 1327 represents an ill-conceived attempt to regulate [drones] use by law enforcement that will leave agencies playing defense against well-equipped private civilians and criminal organizations."
Despite the strong opinions on both sides of the argument, one thing is clear about the bill: It is aimed at getting out in front of an issue that, as of yet, has rarely surfaced. To date, there have only been a small number of cases of police employing drones.
Perhaps the most notable took place in North Dakota, where a farmer was convicted of cattle theft in January based on 2011 surveillance done with a Predator drone -- a military-grade device that's much bigger than the kinds of consumer drones from companies like DJI, Parrot, or 3D Robotics that are increasingly being flown by private individuals in cities and towns across the country.
But public opinion has come down strongly against the use of drones by police departments. Last month, police in San Jose, Calif., were forced to apologize for a lack of transparency related to that department's plans to use the devices. And in June, a Los Angeles crowd gathered to celebrate the world hockey championship by the Los Angeles Kings, knocked a drone out of the sky, believing they were being watched by the police. The device turned out to be privately owned.
Some may question why legislators are seeking to limit law enforcement use of drones, while police remain free to utilize helicopters for surveillance. To Chung, it's very simple. "There is a fundamental difference between helicopters and drones," he said. "The two pieces of technology are very different. It's like comparing a [rotary] telephone to an iPhone."
Chung argued helicopters fly much higher than drones -- which tend to need to be at 500 feet or lower, and that choppers are loud and can stay aloft for only two hours. "A drone can be hovering for more than 24 hours at a time," he said, speaking about equipment like a Predator, "as silent as a hummingbird."
To be sure, most police departments don't have access to Predator drones, and smaller, more inexpensive devices have far shorter battery life and are themselves quite loud. The louder the device, the more likely someone being observed against their wishes will simply move.
Still, Chung said it's incumbent on legislators like his boss to act now, before the FAA comes up with its national drone policy and before an increasing number of police departments acquire drones. "We shouldn't be going into 2015, when drones are going to be authorized for use," he said, "without any laws in place, or it's just going to be like the Wild West."
The police, of course, beg to differ. Many believe that there is little to differentiate between using helicopters and drones for surveillance, and that when someone is in a public place, they are subject to being scrutinized. "I understand [drones] are different than helicopters," said Aaron Maguire, the legislative counsel and representative for the California State Sheriff's Association. "But we think the same expectation of privacy analysis is the same way to look at the issue....If you're going to the 49ers game, or you're in a public arena...we don't think an individual has a reasonable expectation of privacy, and we don't think a warrant makes sense."
Privacy advocates, however, think the public needs more protection from emerging technology. The EFF's Higgins pointed out that the Alameda County (Calif.) sheriff had proposed using drones to monitor protests, and that there is a fear that commonplace drone surveillance photography will soon be combined with facial recognition technology, weakening privacy rights.
Asked why members of the public should be allowed to fly drones that watch the police, but law enforcement should require a warrant, Higgins argued that "that distinction exists in a lot of places, but mostly because you can't go and put someone in jail."